1. Field of the Invention
This invention relates to steering tools. More particularly, the present invention relates to an apparatus for inducing and assisting an electrical tool or the like being lowered down and raised up an oil well bore hole. Even more particulary, the apparatus of the present invention would relate to a steering tool having a combination of directional impellar and thrusting mechanisms, sonic vibration means, and mechanical oscillator means for steering an electrical device down an oil well bore thus maintaining the device in proper postion within the hole enabling the electrical tool to move freely and more rapidly therein.
2. General Background
Due to the ever increasing need for oil, the result or one of the results has been the need to drill oil wells at greater depths in order to reach the oil. As can be expected, in these greater depths, deeper wells are encountering many hazardous drilling problems due mainly to the increased friction, temperatures and pressures which are directly proportional to the increased depth. In the art of drilling oil wells, for each foot that is drilled into the earth, there is an increased pressure of approximately 1/2 pound per square inch on the drilling apparatus. The result being that a zone encountered at a depth, for example, of 2 miles, will have a pressure of approximately 5,000 pounds per square inch. In order to maintain this pressure and prevent it from moving up the bore hole unchecked, which would result in a blow-out and loss of valuable rig time, not to mention perhaps injury to workers and loss of valuable equipment; drilling mud, which is usually a combination of water, dirt and various chemicals, is circulated down the drill pipe, out and around the drill bit and up outside the drill pipe through the drill casing, and back into conditioning pits on the ground, wherein the mud is reconditioned and recirculated back down the drill pipe once more. The need for the drill mud is such that the hydrostatic weight of the column of the drilling mud must always be greater than the pressure of the formation being penetrated or the pressure will overcome the weight of the mud and a blow-out will occur. Obviously greater drilling mud weights are necessary to drill through deeper and higher pressurized zones in todays deeper wells. This deeper drilling also causes many problems within the bore hole due to these higher mud weights, higher temperatures and increased friction. Additional problems within the bore hole are caused by an abundance of deviated bore holes, which are wells drilled intentionally at an angle rather than straight down so that the bottom of the hole will be located at a distance away from the surface location.
Throughout the course of the drilling process, during the completion or recompletion of an oil well, many electrical devices are lowered into the bore hole on what is called a wireline electrical cable from a surface recording unit. Many of the aforementioned drilling problems; increased temperatures, pressure, drilling mud weight and deviated holes, which are all effects of todays deeper drilling, frequently cause these electrical devices to become stuck in the hole, and are many times therefore unretrievable. The loss of one of these electrical devices is not only expensive in itself, but results in the loss of drill time and the loss of very valuable information generated by the unretrieved logging devices. Thus, if the electrical device cannot be retrieved, tools must be lowered into the hole by the drill pipe to either grind up the unretrievable electrical device and retrieve the pieces in a basket, thereby removing the obstacle or redrill the obstructed hole.
An additional problem is encountered in the lowering of these electrical logging devices through the heavy mud weight being used today as heavy mud has a tendency to congeal and even to solidify. The existing electrical devices have reduced weight, of course, when lowered into water, so their weight almost becomes nonexistant when they are placed in a super saturated, heavy drilling mud. Suspension of these devices in the mud causes them to travel very, very slowly down the bore hole and have a tendency to drift within the hole and also to become lodged on any small obstruction within the bore hole. The deep and deviated wells frequently have bridges, ledges and washouts i.e. changes in the diameter of the hole which also cause the electrical devices to hang up, therefore preventing them from getting down to the desired depth.
Several patents have been found in the art which speak to apparatuses for lowering down a drill hole. The most pertinent being as follows:
U.S. Pat. No. 4,166,500 issued to W. A. McPhee entitled "Well Logging Method and Apparatus Using Friction-Reducing Agents" discloses the use of a well logging instrument having a fluid chamber at its lower end which maintains friction reduction agent, and a means in the apparatus for forcing the friction reduction agent into the bore hole at various points along the length to facilitate movement of the apparatus through the bore hole. The apparatus is an electronic instrument that is lowered by cable with electricity being fed along the cable.
U.S. Pat. No. 3,177,938 issued to R. Roussin entitled "Methods and Apparatus for Operating Borehole Equipment" discloses an apparatus which would enable one to operate a tool and a well in various differences in the hydrostatic pressure of the well liquid at different levels in the well. Essentially, the pressure in the apparatus is maintained to the pressure of the hydrostatic pressure at the various levels, and the tube is able to operate at a different level with the pressure in the tube being the same as the hydrostatic pressure.
U.S. Pat. No. 4,192,380 issued to John R. E. Smith entitled "Method and Apparatus for Logging Inclined Earth Boreholes" discloses the method and apparatus of logging formations surrounded earth boreholes by having an elongated well logging instrument connected to the earth's surface by a well logging cable at least two pad members which make contact with the edges of the borehole for transmitting a control signal for operation of the apparatus.
U.S. Pat. No. 3,692,106 issued to E. R. Basham entitled "Apparatus for Ejecting Fluid in a Borehole", U.S. Pat. No. 1,230,666 issued to D. A. Garden entitled "Cleaning Device for Wells" and U.S. Pat. No. 2,187,845 issued to E. Tatalovich entitled "Clean-Out Tool" and U.S. Pat. No. 3,799,276 issued to K. Matsushita entitled "Fluid Driven Below Ground Motor for Sinking a Caisson" all teach various down hole devices.